Summary: Mycroft's CCTV viewing has changed since Sherlock's death.
"They're saying it's lutramania," Anthea told John, as she handed him Mycroft's medical notes.
"Is that a diagnosis?" John replied, flicking through the file, "or a posh psychiatric way of saying 'there's something wrong but we don't know what'?"
"Some kind of fixation, they think. Mr Holmes' mind has become obsessed by a single idea."
"He was OK at Sherlock's funeral."
"That was before they found the CCTV footage from Barts," Anthea replied. "It was then that he finally seemed to realise that Sherlock was dead. He played the tape repeatedly. Then he started playing it backwards, so Sherlock would rise from the pavement and soar back up to the roof alive."
"Oh shit," John said. "That does sound bad."
"We were desperate to distract Mr Holmes," Anthea went on. "Sid Paget found something from a CCTV feed near Wapping, thought it might soothe him. Mr Holmes watched the clip forty-six times non-stop, and then demanded more footage. Said he had to find out what happened to the otter family, whether they were safe."
"Otters. They've returned to a lot of rivers in England now. Including, apparently, the Thames."
"But why does Mycroft want to watch CCTV footage of otters?" John demanded.
"I asked him that," Anthea replied. "And all he said was that they reminded him of his brother."
Note: This was inspired by a recent episode of the BBC wildlife programme Springwatch which included CCTV footage of urban otters.